Recently my gf that I loved more than I have any other person broke up with me and I've been extremely depressed for the last 2 and a half weeks

The past two days I feel a little bit better for about 20 minutes (I'm happy to be making progress) but then soon after that I feel extremely sad for anywhere from 2-3 hours and then I get 20 minutes of feeling betters and it just repeats.

Sometimes it gets really extreme and I start to just break down crying.

I just want to know if this is normal, and if anyone has any advice for me..

Thank you...